Donald Trump hailed the "great relationship" he has with French President Emmanuel Macron and insisted their friendship was "not fake news" as talks got under way in Washington.
The pair appeared to get comfortable with each other as the official welcome ceremony took place on Tuesday, with the two world leaders shaking hands and kissing each other on the cheek, reinforcing the "unity, fraternity and friendship" between the two nations.
The US President said the countries had established a "beautiful friendship forged in revolution" that had "changed the course of history".
It was the first official state visit of Mr Trump's administration.
Mr Trump even appeared to brush "dandruff" off Mr Macron's blazer before calling him "perfect" as they sat down to talk at the White House.
Among the wide-ranging issues up for debate was security, trade and the Iran nuclear deal, which the US leader branded "insane" and "a disaster".
But Mr Trump and Mr Macron vowed to try and resolve differences over Iran, despite the billionaire tycoon not sending a clear signal on whether he would abandon the international nuclear deal with Tehran – which has been seen in the West as preventing Iran from building a nuclear bomb.
At a joint press conference following talks, the French leader said the pair had discussed "a new deal" to strengthen the 2015 accord, taking on Mr Trump's concerns and addressing Iran's expansion in the Middle East and its ballistic missile programme.
The US leader warned of repercussions for Iran if it restarted its nuclear programme. "If Iran threatens us in any way, they will pay a price like few countries have ever paid," he said.
Iran's Foreign Minister Javad Zarif has since said the country would "most likely" abandon the nuclear deal if Mr Trump was to pull the US out of the agreement.
The presidents also discussed the crisis in Syria, with Mr Macron urging his counterpart to keep US forces in the country to ensure the defeat of ISIS militants.
Mr Trump did not promise to keep troops in Syria but did say he would not withdraw forces straight away.
He said: "We want to come home. We'll be coming home. But we want to leave a strong and lasting footprint."
The talks come after the US, France and Britain launched missile strikes in Syria this month to respond to an alleged chemical weapons attack in the town of Douma.
During the talks, the American President also informed Mr Macron that North Korean leader Kim Jong Un – who he called "very open minded" and "honourable" – wanted to meet "as soon as possible".
More from Donald Trump
Earlier in the day, at the welcome ceremony, Mr Macron told Mr Trump, their countries would defeat terrorism, put an end to the threat of nuclear weapons from Iran and North Korea and act together on behalf of the planet, referring to the French leader's efforts to bring the US back into the Paris climate accord.
"History is calling us. It is urging our people to find the fortitude that has guided us in the most difficult of times," said Mr Macron. "France and with it, Europe, and the United States have an appointment with history."